The onset of asthma is often during childhood; and when the child is atopic, the child is more likely to continue to have asthma as an adult. Diseases such as asthma have a higher prevalence in childhood; and management that alters the morbidity of allergic diseases in children may impact disease outcomes in future years.[unreadable] [unreadable] This study examines techniques for the detection of inflammation in children with respiratory diseases due to allergy or immunologic dysfunction. Emphasis is on non-invasive methods. We will use information gathered to determine if there are inflammatory markers that may be diagnostic or representative of disease severity, and thus useful in management.[unreadable] [unreadable] Preliminary data supports the concept of ongoing airway inflammation in asymptomatic children with asthma. It also supports the existing use of nitric oxide as a marker of airway inflammation that may or may not correlate with bronchoconstriction as demonstrated by spiromertry. Furthermore, an elevated expired nitric oxide seen in association with airway inflammation may be associated with a decrease in airway pH, previously documented only during an asthma exacerbation. A similar pattern was not demonstrated in healthy matched controls. [unreadable] [unreadable] Of interest, a small representative sample of exhaled breath condensate was analyzed for several inflammatory cytokines and the results are pending. [unreadable] [unreadable] We are completing the data collection in this longitudinal study of non-invasive measurements of airway inflammation in children with asthma and healthy-matched controls.